1. Field of the Invention
Embodiments of the present invention relate to the field of cable construction. Specifically, embodiments of the present invention relate to a device for deterring cable displacement.
2. Related Art
Cable assemblies are common in a wide spectrum of electrical interconnection applications. Such applications include routing of signals between modules and systems within integrated electronic platforms and chassis. This application is especially widespread in larger platforms such as multi-chassis rack mounted assemblages, an architecture typical of larger computers such as Web and DBMS servers, communications equipment, instrumentation and control panels, and the like.
Exponents of this architecture are routinely designed for compliance with a host of engineering practices and standards. Movement, vibration, and shock are some of the factors taken into account in their mechanical design for reliability. This is helpful, considering that many such assemblages may be designed for portability and transportability, including use while in motion. Further, even equipment designed for stationary mounting and use may be subject to these factors from seismic activity. Thus, even such equipment is also designed with these factors in mind.
Shock and vibration testing is a common modern engineering test practice to verify design intent. They are perhaps one of the more rigorous sources of such phenomena such assemblages may ever encounter. Thus, these assemblages, including that of their electrical terminals and connectors, must be designed to withstand rigorous shock and vibration testing, to certify their compliance to engineering and quality standards, as well as to assure ability to cope with such phenomena in situ.
Peripheral component interconnect (PCI) cards and other printed circuit boards (PCB) in such assemblages are commonly connected to parallel-lying slots, and, in certain applications, are kept separated one from the other in movement, shock, and vibration conditions with electrically insulating planar spacers, such as On-Line Replacement (OLx) dividers. Cables routed within such assemblages are routed in such ways as to minimize their displacement under movement, shock, and vibration conditions.
Cables are typically terminated via their plugs, receptacles, and other such electromechanical appliances installed on each of its ends. These terminals electromechanically couple to complimentary plugs and receptacles installed on components, stages, and/or modules, etc., within the assemblage. This complimentary electromechanical coupling effectuates two useful features.
First, it enables the cables to electrically interconnect components, stages, and/or modules, etc., within the assemblage. For example, a PCI and a module backplane may be electrically coupled via their own accessible receptacles, through a cable and complimentary plugs and receptacles installed on each end thereof. Second, the electromechanical coupling mechanically holds the cable end in place where it is terminated, preventing the electrical intercoupling there from disconnecting inadvertently.
To effectuate the feature of mechanically securing the cable termination, the movement, shock, and vibration design considerations are important. Thus, conventionally, cables terminals are often designed to incorporate lock-on mechanisms of some type. With reference to Prior Art FIG. 1, one common technique to secure the termination of a cable 1C is the use of screw in fasteners, such as a threaded female receptacle 1S on the stationary terminal and a complementary male screw 2M on the cable end. Another common conventional design is a clip 3S on another stationary end, and a complementary clip holder 4M on the cable end.
In some instances however, such lock-on mechanisms may be unavailable. In certain circumstances, this unavailability may be especially likely. For example, in test runs, field repairs, and emergency situations, impromptu cable repairs may be desirable, even necessary, but complementary termination locking hardware may be absent from the parts at hand. Cables terminated under such conditions may lack lockdowns.
Also, when PCIs are added or replaced, off the shelf PCIs frequently have no fasteners available; such boards are simpler and frequently less expensive than boards with such hardware mounted. In some applications, such boards are preferred for another reason; absence of cable locking hardware offers a lower profile and better clearance volume. Thus, cables may lack or lose their lockdowns for the sake of terminals taking up less space.
For a cable lacking terminal securing locking hardware, another conventional technique is illustrated in Prior Art FIG. 2. In this technique, a cable 2C is routed beneath a top cover TC and over the top edges of a set of insulating Olx dividers 202 and 204 to minimize the distance and nonlinearity of its routing path. Cable 2C is terminated by the unlocked electromechanical mating of its own terminating connector 5M and the stationary connector 6S on a PCI board PC2. However, this solution may prove inadequate under significant shock and vibration conditions, as an assemblage may experience under shock and vibration testing and/or in situ.
When shock and vibration testing is applied to assemblages with a cable connected lacking termination fasteners, or when such assemblages are subjected to similar perturbances in situ, it is possible that one or both of the cable terminations may fail under the corresponding stresses and strains. This may be an especially likely danger where the cable""s own length is displaced within the assemblage by movement caused by horizontal, vertical, and torsional forces imposed upon it.
Mechanical failure, e.g., disconnection, of the termination may cause the cable terminal to break free from the complimentary receptacle to which it is coupled. Such disconnections result in electrical decoupling, with corresponding interruption of signals, control, power, and communications flow, and related, incidental and consequential failures, including system shutdowns, crashes, etc.
Hence, conventional cable assemblies are often susceptible to damage or disconnection due to mechanical movement, shock, and/or vibration, especially when employed without a terminating fastener.
A device for deterring displacement of a cable is effectuated in an embodiment of the invention by an enclosure adapted to envelope the cable and an affixing mechanism adapted to couple the enclosure to the cable. The cable is oriented in an assembly such that the enclosure contacts a feature internal to the assembly and deters displacement of the cable.